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Discussion Starter #1
I ran my buick last night and I think i'm very close on my tune. Nothing big, just a small plate on a sbc, 57N 53F. 975 bottle pressure, 5.5 fuel. I've been using 100 octane pump gas and I can't seem to run much timing without still peppering the plugs a tiny bit. I am pulling 14 degrees out of 36 when the juice is flowing. I have a thin and light carbon ring at the base of the porcelean and it was reading 12.0-12.2 on the AFR gauge.

Below are pics of plugs from last night. From left to right:

1)n/a pass
2)pulling 10 degrees - few black specks
3)pulling 12 degrees - even fewer
4)pulling 14 degrees - no specks

I don't have a good feeling for reading the straps. How do mine look? The next time I go out I'm going to run 110 octane leaded fuel and try to put some timing back in. This plate is taking me from [email protected] down to [email protected] I slowed .1 with all 14 degrees out.




 

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pig hunter
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black speck could be carbon burning off the top of the pistons or a little oil in the cylinder.. what engine is this and comp..
 

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Discussion Starter #4
Here is the setup overview:

1984 Buick Regal
383 sbc 11:1
Forged flat top pistons w/2 valve reliefs
Eagle rods
Engine Quest Heads. 200cc intake runners, 64 cc chambers
Crower Solid Roller 00426S grind
ADV Duration 288/290 Lift .570 .584
Duration @ .050 250/252
108 Lobe Center
.026/.028 Valve clearance
Comp 1.5 Stainless Rockers
Crower springs
Victor JR intake
Holley 750 Double Pumper with Proform main body
Hooker headers, small primaries, 3" collectors
3" dual exhaust w/x-pipe, no cats, mandrel bent
700R4 Trans -built
4000 Stall 10" w/full size lockup plate.
4.11 Gears
27x11.50x15 Hoosiers
Car weighs 3450 lbs
100 hp nitrous plate system
Accel Nitrous Mastermind
Distributor locked at 36 degrees
100 Octane unleaded fuel
 

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Discussion Starter #5
I had wondered if it could be carbon. Would it only leave the carbon specs when the nitrous is used? How can I tell the difference? The specks are so tiny they are hard to take a picture of.
 

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Discussion Starter #6
I got a couple close up pics of the "worst" plug. Does it look like carbon?


 

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Discussion Starter #11
Yea it does sound strange pulling that much for a small hit. That is why I'm checking with the experts here. Do the specks on the plugs look like carbon or something else? For all I know I could be pulling way too much timing.
 

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I assume they were fresh plugs before the pass. I get the same thing on mine if I have been street driving, I usually point to the tops of the pistons getting "cleaned off" as Jeff mentioned.
 

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Discussion Starter #13
The first pass was n/a and showed zero specks. Plugs were fresh each pass. When I've seen aluminum on plugs in the past it was more like 3 dimensional specks or gray spots.
 

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Discussion Starter #15
What would cause that? From what I'm reading I was going the wrong way with the timing if it was slowing down.
 

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I've seen those black specs a few times while moving tunes around. I'm pretty sure mine are usually a combination of being a little low on timing and way rich on the intermediates (burnout and on the chip).
 

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Is it an Edelbrock Performer plate? If so is the Edelbrock suggested jetting for the 100 horse hit 57n/65f or something close to that? I ask because I have an Edelbrock Performer kit and I believe that's their suggested jetting and I think that's gonna be way off and I was wondering where to start.

Hope I don't seem to be high-jacking your thread but I'm a nitrous newb so wanted to ask. Thanks.
 

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Discussion Starter #20
It is the larger of the two Edelbrock plates, whichever that one is. I'm headed to the track in a few minutes for some more tuning.
 
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